<template>
  <div class="article-container">
    <!-- 导航栏 -->
    <van-nav-bar
      class="page-nav-bar"
      left-arrow
      title="黑马头条"
      @click-left="$router.back()"
    ></van-nav-bar>
    <!-- /导航栏 -->

    <div class="main-wrap">
      <!-- 加载中 -->
      <div class="loading-wrap" v-if="requestStatus === 0">
        <van-loading color="#3296fa" vertical>加载中</van-loading>
      </div>
      <!-- /加载中 -->

      <!-- 加载完成-文章详情 -->
      <div class="article-detail" v-else-if="requestStatus === 1">
        <!-- 文章标题 -->
        <h1 class="article-title">{{ article.title }}</h1>
        <!-- /文章标题 -->

        <!-- 用户信息 -->
        <van-cell class="user-info" center :border="false">
          <van-image
            class="avatar"
            slot="icon"
            round
            fit="cover"
            :src="article.aut_photo"
          />
          <div slot="title" class="user-name">{{ article.aut_name }}</div>
          <div slot="label" class="publish-date">
            {{ article.pubdate | relativeTime }}
          </div>
          <!-- 当传给子组件既要使用数据又要修改数据 可以使用 v-model -->
          <FollowUser
            class="follow-btn"
            @update-is-followed="article.is_followed = $event"
            v-model="article.is_followed"
            :userId="article.aut_id"
          />
        </van-cell>
        <!-- /用户信息 -->

        <!-- 文章内容 -->
        <div
          class="article-content markdown-body"
          v-html="article.content"
          ref="article-content"
        ></div>
        <van-divider>正文结束</van-divider>

        <!-- 文章评论列表 -->
        <CommentList
          :articleId="article.art_id"
          @onload-succuess="totalCommentCount = $event.total_count"
          :list="commentList"
          @reply-click="onReplyClick"
        />
        <!-- /文章评论列表 -->

        <!-- 底部区域 -->
        <div class="article-bottom">
          <van-button
            class="comment-btn"
            type="default"
            round
            size="small"
            @click="isPostShow = true"
            >写评论</van-button
          >
          <van-icon name="comment-o" :badge="totalCommentCount" color="#777" />
          <!-- 收藏 -->
          <CollectArticle
            v-model="article.is_collected"
            :articleId="article.art_id"
          />
          <!-- 点赞 -->
          <LikeArticle v-model="article.attitude" :articleId="article.art_id" />
          <van-icon name="share" color="#777777"></van-icon>
        </div>
        <!-- /底部区域 -->
      </div>
      <!-- /加载完成-文章详情 -->

      <!-- 加载失败：404 -->
      <div class="error-wrap" v-else-if="requestStatus === 404">
        <van-icon name="failure" />
        <p class="text">该资源不存在或已删除!</p>
      </div>
      <!-- /加载失败：404 -->

      <!-- 加载失败：其它未知错误（例如网络原因或服务端异常） -->
      <div class="error-wrap" v-else>
        <van-icon name="failure" />
        <p class="text">内容加载失败!</p>
        <van-button class="retry-btn" @click="loadArticle">点击重试</van-button>
      </div>
      <!-- /加载失败：其它未知错误（例如网络原因或服务端异常） -->
    </div>
    <!-- 图片预览 -->
    <van-image-preview
      v-model="preImgIsShow"
      :images="images"
      showIndex
      @change="onchange"
      :start-position="index"
      :overlay-style="{
        background:
          'linear-gradient(120deg, hsla(339, 100%, 55%, .8) 0%, hsla(197, 100%, 64%, .8) 100%)'
      }"
    >
      <template #index>第{{ index }}页 / 共{{ images.length }}页</template>
    </van-image-preview>
    <!-- /图片预览 -->
    <!-- 发布评论弹出层 -->
    <van-popup v-model="isPostShow" position="bottom">
      <CommentPost :target="article.art_id" @post-success="onPostSucces" />
    </van-popup>
    <!-- /发布评论弹出层 -->
    <!-- 回复评论弹出层 -->
    <van-popup
      v-model="isReplyShow"
      position="bottom"
      :style="{ height: '93%' }"
    >
      <CommentReply
        :comment="replyComment"
        @close="isReplyShow = false"
        v-if="isReplyShow"
        :articleId="article.art_id"
      />
    </van-popup>
    <!-- /回复评论弹出层 -->
  </div>
</template>

<script>
import FollowUser from '@/components/FollowUser.vue'
import CollectArticle from '../../components/CollectArticle.vue'
import LikeArticle from '../../components/LikeArticle.vue'
import CommentList from './components/comment-list.vue'
import CommentPost from './components/commnet-post.vue'
import CommentReply from './components/comment-reply.vue'
export default {
  name: 'ArticleIndex',
  provide() {
    return {
      articleId: this.article.art_id
    }
  },
  components: {
    FollowUser,
    CollectArticle,
    LikeArticle,
    CommentList,
    CommentPost,
    CommentReply
  },
  data() {
    return {
      article: {}, // 文章详情
      requestStatus: 1, // 请求状态控制显示 0 加载中 1 文章加载完成 404 文章不存在 其他 请求失败
      preImgIsShow: false, // 控制图片预览的展示与隐藏
      images: [], // 图片预览的src数组
      index: 0,
      totalCommentCount: 0, // 评论个数
      isPostShow: false, // 控制发布评论弹出层的显示与隐藏
      commentList: [], // 评论列表
      isReplyShow: false, // 控制回复的显示状态
      replyComment: {} // 当前回复评论
    }
  },
  props: {
    articleId: {
      type: [Number, String],
      required: true
    }
  },
  created() {
    this.loadArticle()
  },
  methods: {
    async loadArticle() {
      this.requestStatus = 0
      try {
        const { data: res } = await this.$api.getArticleById(this.articleId)
        // if (Math.random() > 0.5) throw new Error() // 测试代码 捕获异常
        this.article = res.data
        this.requestStatus = 1
        this.$nextTick(() => {
          this.previewImages()
        })
      } catch (err) {
        if (err.response && err.response.status) {
          this.requestStatus = err.response.status
        } else {
          this.requestStatus = 999999 // 错误对象没有 status 手动调整状态
        }
      }
    },
    previewImages() {
      const articleContent = this.$refs['article-content']
      const imgs = articleContent.querySelectorAll('img')
      const images = []
      imgs.forEach((item, index) => {
        images.push(item.src)
        item.onclick = () => {
          this.preImgIsShow = true
          this.index = index
        }
      })
      this.images = images
    },
    onchange(index) {
      this.index = index
    },
    // 评论发布成功
    onPostSucces(data) {
      this.isPostShow = false
      console.log(data)
      this.commentList.unshift(data.new_obj)
    },
    onReplyClick(comment) {
      this.replyComment = comment
      this.isReplyShow = true
    }
  }
}
</script>

<style scoped lang="less">
@import url('./github-markdown.css');
.article-container {
  .main-wrap {
    position: fixed;
    left: 0;
    right: 0;
    top: 92px;
    bottom: 88px;
    overflow-y: scroll;
    background-color: #fff;
  }
  .article-detail {
    .article-title {
      font-size: 40px;
      padding: 50px 32px;
      margin: 0;
      color: #3a3a3a;
    }

    .user-info {
      padding: 0 32px;
      .avatar {
        width: 70px;
        height: 70px;
        margin-right: 17px;
      }
      .van-cell__label {
        margin-top: 0;
      }
      .user-name {
        font-size: 24px;
        color: #3a3a3a;
      }
      .publish-date {
        font-size: 23px;
        color: #b7b7b7;
      }
      .follow-btn {
        width: 170px;
        height: 58px;
      }
    }

    .article-content {
      padding: 55px 32px;
      /deep/ p {
        text-align: justify;
      }
    }
  }

  .loading-wrap {
    padding: 200px 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #fff;
  }

  .error-wrap {
    padding: 200px 32px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background-color: #fff;
    .van-icon {
      font-size: 122px;
      color: #b4b4b4;
    }
    .text {
      font-size: 30px;
      color: #666666;
      margin: 33px 0 46px;
    }
    .retry-btn {
      width: 280px;
      height: 70px;
      line-height: 70px;
      border: 1px solid #c3c3c3;
      font-size: 30px;
      color: #666666;
    }
  }

  .article-bottom {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    justify-content: space-around;
    align-items: center;
    box-sizing: border-box;
    height: 88px;
    border-top: 1px solid #d8d8d8;
    background-color: #fff;
    .comment-btn {
      width: 282px;
      height: 46px;
      border: 2px solid #eeeeee;
      font-size: 30px;
      line-height: 46px;
      color: #a7a7a7;
    }
    /deep/ .van-icon {
      font-size: 40px;
      .van-info {
        font-size: 16px;
        background-color: #e22829;
      }
    }
  }
}
</style>
